9 Best Brake Fluid Testers Reviews 2024

Tech is a great thing – in most cases because many tools that were once the preserve of the experts are easily accessible to all enthusiastic car owners. A particular example is the DIY brake fluid tools. Typically, we ought to maintain a good brake fluid condition for efficiency in the braking system.

For a while, brake fluid test strips have been in use to measure brake fluid’s mineral or moisture content. However, these chemical strips can be costly, and they have to be disposed of after use. Fortunately, modern technology led to the invention of an LED brake fluid tester. The LED brake fluid tester is inexpensive, reusable, and more accurate.

It is recommended that you utilize the best brake fluid tester because moisture content varies depending on the type of brake fluid, the driving environment, and the vehicle’s performance design. However, with so many tools to choose from, it can be a difficult decision, but this article has done all the hard work for you.

Our Top 3 Brake Fluid Moisture Testers

Best Brake Fluid Tester Reviews

01. ITEQ Brake Fluid Tester Pen

The ITEQ Brake fluid tester pen is high quality and fast fluid tester that has 5 LED indicators that are calibrated for cars using DOT3 and DOT4 fluids. To use it, you only need to turn it on by pressing the power button on top. Green color shows no water, yellow/yellow 1% of water, red 3%, and red/red 4% water content. A red color tells you that the brake fluid needs to be changed. After each use, its test probe should be washed with tap water.

The ITEQ tester is calibrated only for DOT4 and DOT3 fluids but not for DOT5. In case your skin comes into contact with the brake fluid, wash the affected part thoroughly.

  • It takes only Seconds to get the Results
  • Calibrated for Vehicles using DOT4 and DOT3 fluids
  • CE and RoH5 Approved
  • LED Colors Show the Percentage of Water in the Brake Fluid

02. PTE Tester

The PTE is undoubtedly a great option if you are looking for brake fluid tester reliability. It is calibrated to make it easier to read and interpret results and is also cheaper than most of the other options. It also works by showing the percentage levels of water in the fluid. A percentage of 4 or 3 tells you that you need to be draining the brake fluid and replace it with a new one.

It requires 2 AAA batteries and is only used for DOT4 FLUID. This tester pen quickly determines whether you need to change your brake fluid. This also prevents you from exposing the brake fluid to the atmosphere for long because it is hygroscopic.

  • LED indicators that indicate the volume in the percentage of water
  • Delivers results in a few seconds
  • Uses 1.5V battery
  • Calibrated for vehicles using DOT4 fluid
  • Easy and fast way to test the moisture content

03. eOUTIL tester

eOUTIL brake fluid tester is one of the most accurate in the market. Its only downside is that its case is not that much resistant o the brake fluid. You should, therefore, be very cautious and wash it rigorously with the tester is undoubtedly a piece of high-quality equipment that could even be used by an actual mechanic. It can be used to test the water content in both DOT3 and DOT4 brake fluids.

It was developed for use in professional automotive repair shops as well as servicing of vehicles. It has 5 LEDs that work to show the corresponding percentage of water in the brake fluid. It is also operated a 1.5V AAA battery.

  • Designed for Professional Use
  • It has 5 LEDs to Show the Water Percentage
  • Operated by LRO3 AAA Battery (1.5V)
  • A Digital Tester Great for Testing a Vehicle’s Brake Fluid Quality

04. OTC 4598 Brake Fluid Tester

The OTC 4598 brake fluid tester helps one detect bad brake fluid before it destroys the brake system components such as the expensive brake calipers. It determines the quality of DOT3 fluid and also measures moisture content from 0-4%. It shuts off automatically after 12 seconds if not in use. The tester is easy to use and interpret.

When you power it on, the tester goes through a self-test, and the green light stays on, showing that the fluid tester is ready to test for moisture. It works well, and you get to save time and money. The tester can serve you for a long time as long as you take good care of it.

  • DOT3 Brake Fluid Tester
  • It Measures Moisture Level from 0%-4%
  • 1.5V AAA Battery
  • Shuts off Automatically After 12 seconds
  • Has LED Lights that Show the Percentage of Moisture

05. Automotive Brake Fluid Tester

On most brake fluid tester reviews, the automotive brake fluid tester with an oil inspection gooseneck never misses. It is certainly one of the best testers for DOT3 to DOT4 to DOT5 brake fluids. Its packaging includes a user manual and a brake fluid tester, although it does not come with a battery.

The tester its extended gooseneck helps ensure flexibility of detection. It is an excellent product if you have to test multiple vehicles and different fluids as well. The tester measures water content in a percentage of up to 4%. A reading above 1.5% tells you that you need to drain and replace the brake fluid.

  • It tests the water-to-brake fluid ratio scale
  • It has a 250mm gooseneck probe that gives the flexibility for detection
  • The chromed detector that is resistant to oxidation and oils
  • Red light double and buzzing alarm system
  • One-hand operation

06. BELEY Automotive Tester

The BELEY fluid tester comes in a great design, can test all types of brake fluids, from DOT3, DO4 to DOT5. If you are not sure the type of brake fluid your vehicle uses by simply looking at the brake fluid color, you can use this tester, which would work just fine. It uses a 9V battery that is sold separately. It powers up and lets the user audibly know that it is ready.

Changing modes is as easy as a single button press. It usually feels light while on your hand despite its body size, but it has a great grip. It has a great and durable ABS plastic that is well-made easy to read. Its accuracy is unmatched, thus making it reliable. A much similar model but with a 2.2” LCD for cars is theBELEY Tester with 2.2” LCD.

  • Premium Design
  • It is Convenient due to a Perfect Size and Clear Results
  • Quality Warranty up to 24 Months
  • Universal fit for Many Vehicles

07. Mrcartool Tester

The Mrcartool brake fluid tester is a fantastic tool to use with all types of brake fluid. This tool is a must-have to ensure safe driving. It tests the water-to-brake fluid ratio in percentage to help you do maintenance. The test results are usually clear and accurate.

It determines the quality of the brake fluid and also measures moisture content from 0-4%. It shuts off automatically after 12 seconds if not in use. The tester is easy to use and interpret. A reading above 1.5% tells you that you need to drain and replace the brake fluid. If it has been in use for long, it is best to remove all the batteries and store them in a cool, dry place.

  • Hand-held size
  • Red light and buzzing double alarm system
  • Chromed detector resistant to oxidation and oils
  • A 250mm gooseneck

08. VXSCAN Auto Tool

The VXSCAN tool is a simple, economical, and reasonably accurate tool that tests the presence of any moisture in brake fluids. It works well and is very easy to use. You only need to put in the battery, place the probes in the reservoir, and start testing almost as soon.

For an affordable price, you get a lot more than what you pay for. A quality warranty is also offered in case the product you receive does not work. You should take good care of the product to ensure it lasts long and serves you well. This tester pen quickly determines whether you need to change your brake fluid. To use it, press the power button, and the green LED lights up. Insert the VXSCAN into the reservoir for a second and then read the results.

  • Accurate
  • Fast
  • Small and compact
  • 1.5V Battery

09. OEMTOOLS 25269

The OEM tools brake fluid tester 25269 is a handy pocket brake fluid tester that is easily portable from one place to the other. It is a brake fluid tester for DOT 3, 4, and 5.1 brake fluids. It comes from a trustworthy manufacturer, and it is made to fit international standards. The tester simply never disappoints. After use, it turns itself off after a period of inactivity.

It is easy to change between fluids as it is easy to interpret. It comes with a full instructions manual. Most people like it because it can be pocketed and carried around, making it a handy pocket brake fluid tester. Also, it comes with a quality warranty.

  • Handy Tester with a Pocket Retaining Clip
  • Built-in Self-Test
  • AAA Battery
  • Simple Push Button for Changing Fluid Types
  • Auto-Off
  • Complete Instructions Manual
  • Quick, Accurate Results
  • Built-in LED light

Using a Brake Fluid Tester

Usually, manufacturers have a specified mileage or period, after which you need to change the brake fluid. For the test, you would need a dirty cloth, a pentester, or a multimeter and the knowledge on how to test brake fluid with a multimeter or an LED pen.

A test can be completed in just a few minutes, say 2 to 5. You should find an LED pen that is compatible with your vehicle’s brake fluid type, whether DOT3, 4 or 5, because not all work for all fluids. You should then locate the brake fluid reservoir, normally located on the firewall. Wipe off surrounding areas before you open it, to avoid introducing contaminants into the fluid.

Power up the tester, and the green light turns on automatically. Select the mode for the type of brake fluid you are using, and then remove the protective cap from the pen. Remove the caps and dip the probes into the brake fluid and watch the reading. The readings are usually from 0-4%, with 4 being the highest percentage, which necessitates a fluid change.

After removing the probes, wipe them off and close the reservoir almost as immediately. For a detailed illustration, watch this video:

What to Consider While Buying a Brake Fluid Tester

1. Type of Brake Fluid

Before you commit yourself to buy a brake fluid tester, you have to double-check to ensure that it is compatible with the type of brake fluid your vehicle uses. Different types of brake fluids absorb moisture at different rates. Thus it would not be advisable to use the same tester for all fluids. If it has to be one tester for your various vehicles, ensure it can measure all types of brake fluid first.

2. Build Quality

This is one of the main considerations you ought to consider. If a tester is not of excellent build quality, then it would most likely disappoint you or offer inaccurate results. Just like any other investment, you have to carry out due research on the best and most trustworthy manufacturers before spending your hard-earned money on a tool that will not even last two or three uses.

Moreover, some testers are made to measure the water ratio in a few seconds; hence they have very sensitive probes.

3. Specific Features and Other Accessories

Some brake fluid testers have better features than others that enable ease of use and more accurate results. For instance, one may have LED lights to show the corresponding percentage of water, while others show the percentage on a screen. One LED fluid tester pen may come with a free battery, while in others, you have to buy it separately.

4. Price

Price is also important to consider, although it does not always guarantee quality. You should only buy what you can afford. Always have in mind that an expensive tester does not mean that it is the best in the market. You can find cheaper options that offer similar or even better efficiency. On the same note, you would not expect a cheaply priced brake fluid tester to give the most accurate results or reliable service.

Look for various products review and see what other customers have to say about a particular product you are interested in. If most people claim that it is good, then it is highly likely to perform well or even beyond your expectations.

Lastly, if its design appeals to you, go for it. Always look at all specs a tester has to offer. Put your taste or preference into consideration, and from best brake fluid tester reviews, you can narrow down to an option that you think would work great for you. The most important thing to consider is whether it suits your vehicle’s brake fluid as well as its trustworthiness in terms of delivering professional-grade results.


how to test brake fluid

What Does a Brake Fluid Tester Do?

Brake fluid gradually absorbs moisture due to its hygroscopic nature. A brake fluid tester measures the ratio of moisture content in a vehicle’s brake fluid. It gives accurate results in seconds and thus allows the reader to identify the cars that need a change of brake fluid.

As a result, it contributes to increased sales of brake fluid flushes and brake fluid. These testers work through the boiling point method, which is the only approved method that gives reliable and accurate results. The brake fluid tester thus helps you decide whether it is still safe to use the current brake fluid or not.

What Happens If You Put Antifreeze In Your Brake Fluid?

Antifreeze is only meant to be in a coolant fluid as it alters the boiling and melting points of a fluid. If you add antifreeze into the brake fluid, it will almost function as normally. However, the brake light on the dash may light, indicating there is a problem with your braking system. The coolant may end up ruining the expensive calipers, rubber brake hoses, brake master cylinder, and other components.

It is thus advisable to flush the entire brake fluid to avoid chemical reactions that may pose a potential safety hazard to your life and that of other motorists. Eventually, brake failure may result.

How Do You Test Brake Fluid For Contamination?

You require plastic gloves and a brake fluid test kit for this DIT project. To check your vehicle’s brake fluid for contamination, remove the master cylinder cover and then dip a testing strip into the fluid. Immediately after you remove the test strip, replace the master cylinder cover to prevent it from absorbing moisture.

Shake off the excess fluid from the test strip while preventing the fluid from coming into contact with your skin, clothes, or car paint. Wait for about sixty seconds before you compare the strips’ resultant color with that of the guide on the brake fluid tests package. The guide will tell you if it is time to change the brake fluid.

Does Brake Fluid Mix With Water?

In the short term, the brakes work perfectly okay. However, brake fluid is said to be hygroscopic. This means that it has a high ability to absorb moisture from the atmosphere, and thus it should remain airtight all the time.

It is not allowed to mix with water, but after a long time, it absorbs some water, which reduces its overall efficiency. Once the fluid tests to contain water above 2%, then it is time to change the fluid before it corrodes the internal parts of the braking system.

What Is Better DOT 3 or DOT 4?

Both DOT3 and DOT4 fluids are glycol ether-based. They are mainly used in modern trucks and cars because they are compatible with ABS brakes. The main difference between the two is their boiling points. In as much as DOT4 has a higher boiling point than DOT3, they are both compatible and hence can be mixed.

professional brake fluid tester


Moisture-laden brake fluids may cause metallic components in the braking system to corrode and rust, which results in your brake fluid having rust particles. You should always ensure the brake fluid reservoir cap is closed tightly to prevent dirt or any debris from making its way into the braking system. The results would be reduced efficiency in the braking system, which is a safety concern.

For most vehicles, the time to change brake fluid is usually indicated in the owner’s manual, but if you are not sure, use the best brake fluid tester to determine if it is already time to drain the brake fluid. Your safety and that of other motorists matter at all times; thus, the braking system should never be taken for granted.

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Hi there, I am R. Hasan Tito, a mechanic, and owner of this website. My friend and I created this website to share our knowledge, expertise, and experience with our fellow mechanics' community and car users. I am a specialist and certified automotive mechanic (Both Heavy Commercial and Private Cars). I worked as a Mechanic and Mechanic Supervisor for over fifteen years at Global Rebound Automotive companies - Toyota, TATA, BMW, Nissan, TVs, and Others. Now, I enjoy my new role of leading a team of automotive experts (in their respective fields) and publish new content on a regular basis on my website and social media.

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